The present invention relates to a switching device for the protection of direct current devices such as batteries, accumulators, direct current electrical machines and direct current electrical appliances against for example one or more of excess current, excess temperature and low-tension voltage.
For the protection of vehicular batteries quickbreak fuses have already been employed but experience has shown that the batteries are destroyed without the fuses responding.
The present invention is based on the problem of devising a switching device of the above described kind whereby the current circuit is interrupted upon the occurrence of excess current, excessive heat or unduly low voltage; harmful and powerful arcing resulting from high direct voltages of e.g. 110, 144, 220, 360, 500 V being prevented.